THE CROSS OF CONSTANTINE.

THE following beautiful stanzas were written in the album of a friend, by the lamented Lady Flora Hastings, so long since as 1833: six years before they became so touchingly applicable to her own state of trial, of suffering, of conflict, and of victory. They exactly express what was well known to be the conviction of her own mind-the feeling of her own heart; and as such they now furnish a rich consolation to her sorrowing friends.

'CONQUER in this!' not unto thee alone

The vision spake, imperial Constantine; Nor presage only of an earthly throne

Blazed in mid heaven the consecrated sign: Thro' the unmeasur'd tract of coming time,

The mystic cross doth with soft lustre glow; And speaks, through ev'ry age, in ev'ry clime, To ev'ry slave of sin and child of woe.

Conquer in this!" Ay, when the rebel heart
Clings to the idols it was wont to cherish,

And, as it sees those fleeting boons depart,

Grieveth that things so bright were formed to perish. Arise, bereav'd one! and athwart the gloom, Read in the brightness of that cheering ray"Mourn not, O Christian, tho' so brief their bloom, Nought that is worth a sigh shall pass away!"

"Conquer in this!" when fairest visions come, To lure thy spirit to a path of flowers; Binding the exile from a heav'nly home

To dwell a lingerer in unholy bowers;

Strong in his strength who burst the bonds of sin
Clasp, to thy bosom clasp the holy cross!
Dost thou not seek a heav'nly crown to win?
Hast thou not counted all beside but loss?

66

Conquer in this!" tho' powers of earth and hell Were leagued to bar thee from thy heavenward way, The Cross shall ev'ry darkling shade dispel,

Chase ev'ry doubt, and re-assure dismay.
Faint not, oh, wearied one; faint not-for thee
The Lord of Righteousness and Glory bled,
And his good Spirit's influence, with free
And plenteous unction, is upon thee shed.

"Conquer in this!" when by thy fever'd bed

Thou see'st the dark-winged angel take his stand, Who soon shall lay thy body with the dead, And bear thy spirit to the spirits' land. Fear not-the Cross sustains thee, and its aid In that last trial shall thy succour bring; Go fearless thro' the dark, the untried shade, For sin is banish'd, and death hath no sting!

ASTRONOMY.

Continued from vol. xi. p. 434.

THE cause of tides was discovered by Kepler, who thus explains it :- All bodies attract each other, and were it not for the superior attraction of the earth, the waters would rise up and fall to the moon.' This idea Newton instantly seized and demonstrated. The waters on the side of the earth next the moon are more attracted than the central parts, and the central parts of the earth, or those 90 degrees from the former, are more attracted than the waters on the opposite side of the moon; and therefore the distance between the earth's centre and the waters on its surface, under and opposite to the moon, will be increased. But the latter, or the tide opposite to the moon, will not be so high as that immediately under her. Hence, as the earth turns around on its axis from moon to moon again in 24 hours, there will be two tides of flood, and two of ebb in that time—each tide being 6 hrs. 12 min. after the preceding. The sun likewise assists in raising the tides, so that if there were no moon, there would still be tides, although not so high; but because of the distance of the sun, his influence, notwithstanding his magnitude, is so inferior that he could not raise them more one-fifth as much as the lesser luminary. When the sun and moon act in unison, as at new and full moon,

the tides become very elevated; for while the moon raises the waters nine feet, and the sun two feet, their united influence will raise them eleven feet; but when their influence is opposed, as at the first and third quarters, they will only be raised seven feet.

When the Moon is in conjunction or opposition, as in the former case, the tides are called spring tides, when in the quadratures, as in the latter case, they are called neap tides.'

With us, or in any latitude north of the equator, the greatest spring tides occur when the moon has the greatest northern declination. But with the whole earth, taken collectively, the greatest spring-tides occur a little before the vernal and a little after the autumnal equinox, also at two or three days after the full or change of the moon, when the moon is in perigee, and in summer evenings and winter mornings. Inland seas, as the Mediterranean, Baltic and Black Seas, and Lakes, have no sensible tides, for the moon when on the meridian attracts nearly every part alike, and the communication of the former with the ocean is so narrow that they cannot receive or give enough to make any sensible elevation or depression. The tide which sets on the eastern coast of Great Britain comes from the north sea, from whence it is 12 hours in coming to London Bridge, where it arrives by the time that another tide is raised in the north sea. It is high tide at Aberdeen at the full and change of the moon, about past 12; at Hull at 6; at Harwich at 103; at the Nore at 12; and at London Bridge it will be 3 o'clock. While one tide goes round the north coast of Great Britain,

Spring tides are the greatest high tides, and the greatest low tides. Neap tides are the least high tides, and the least low tides.

another enters the English channel, so as to meet the former near the Goodwin Sands.

The air being lighter than water, the moon must raise higher tides in it than in the sea: and it is a well known fact that the greatest storms take place at the equinox when the tides are highest.

Whatever affects the atmosphere affects the human body. History affords us many instances of this; for example, Lord Bacon was always affected by the change of the moon.

Eclipses. By eclipses are meant the sudden darkenings of the sun and moon. Until the true cause of eclipses was known, these phenomenas were considered supernatural, and were viewed with the greatest awe and reverence. Some conceived that the extinction of light was occasioned by the finger of God, as a token of displeasure; some that the heavenly body was the victim of enchantment, and would be taken from them, but for the noise made on such occasions. Plutarch informs us that the Romans were not allowed to talk of the causes of eclipses. Isaiah and other sacred writers speak of them as indicative of the wrath of the Almighty.

If a body be exposed to the light of the sun, or any' other luminary, a shadow will be caused by the interception of its rays opposite to that luminary. The moon, therefore, in passing through the shadow of the earth must be deprived of her light from the sun, or suffer an eclipse; and the earth in passing through the shadow of the moon suffers an eclipse, which is called an eclipse of the sun. So that there cannot be an eclipse of the sun, but at new moon; or when the moon is in conjunction with the sun; nor an eclipse of the moon but at full moon, or when the moon is in